EP1538256B1 - Réalisation du profil des matières solides dissoutes - Google Patents

Réalisation du profil des matières solides dissoutes Download PDF

Info

Publication number
EP1538256B1
EP1538256B1 EP04028909A EP04028909A EP1538256B1 EP 1538256 B1 EP1538256 B1 EP 1538256B1 EP 04028909 A EP04028909 A EP 04028909A EP 04028909 A EP04028909 A EP 04028909A EP 1538256 B1 EP1538256 B1 EP 1538256B1
Authority
EP
European Patent Office
Prior art keywords
digester
liquid
dom
level
branch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP04028909A
Other languages
German (de)
English (en)
Other versions
EP1538256A2 (fr
EP1538256A3 (fr
Inventor
Bruno S. Marcoccia
J. Robert Prough
Richard O. Laakso
R. Fred Chasse
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Andritz Inc
Original Assignee
Andritz Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=22525038&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP1538256(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Andritz Inc filed Critical Andritz Inc
Publication of EP1538256A2 publication Critical patent/EP1538256A2/fr
Publication of EP1538256A3 publication Critical patent/EP1538256A3/fr
Application granted granted Critical
Publication of EP1538256B1 publication Critical patent/EP1538256B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/02—Pulping cellulose-containing materials with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/0021—Introduction of various effluents, e.g. waste waters, into the pulping, recovery and regeneration cycle (closed-cycle)
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/04—Regeneration of pulp liquors or effluent waste waters of alkali lye
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/02—Pulping cellulose-containing materials with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
    • D21C3/022—Pulping cellulose-containing materials with inorganic bases or alkaline reacting compounds, e.g. sulfate processes in presence of S-containing compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/22—Other features of pulping processes
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/22—Other features of pulping processes
    • D21C3/224—Use of means other than pressure and temperature
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/22—Other features of pulping processes
    • D21C3/24—Continuous processes
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C7/00—Digesters
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C7/00—Digesters
    • D21C7/12—Devices for regulating or controlling
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C7/00—Digesters
    • D21C7/14—Means for circulating the lye
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
    • D21G7/00—Damping devices

Definitions

  • DOM dissolved organic materials
  • US 3 802 956 A discloses a two vessel continuous digester system, wherein a steam phase is maintained in the upper part of the digester vessel, a level tank being operatively connected to a chip chute feeding a high pressure transfer device from which the chips are fed to the top of the impregnation vessel.
  • EP 0 344 462 A discloses a similar two vessel steam phase digester system (Fig. 4) although the chips are fed into the bottom of the impregnation vessel.
  • US 3 215 588 A discloses a high-temperature vapour-phase continuous cooking system, wherein the digester has a zone wherein the chips are rapidly and uniformly heated and cooked in vapour phase, with continuous movement of the chips from such zone into a succeeding zone in which the chips are immersed in a liquid provided for extraction of solubilized amorphous material.
  • US 4 670 098 A discloses a process for preparing cellulose pulp in a two vessel continuous digester system, wherein in a pulping zone substances having a certain molecular weight are separated and removed from the ligno cellulosic material and become dispersed in the pulping liquor, such liquor being withdrawn and such dispersed substances being removed therefrom, whereafter the pulping liquor is returned to the pulping zone.
  • a vapor phase continuous digester system and method of treating comminuted cellulosic fibrous material are provided which facilitate practical implementation of the DOM level control concepts.
  • various advantageous results are obtained, some of them by using unexpected techniques, others by using conventional equipment but in new manners.
  • adding white liquor at numerous points and levels in a continuous digester, and adding low effective DOM dilution liquids too means that less liquid is available to transport chips during and after impregnation, that is from the high pressure transfer device to the digester.
  • the amount of alkali fed to the feed system in digester systems controlling DOM may be as low as 40-55% (e. g. less than about 55%).
  • liquid is withdrawn from the circulation line from the top of the digester to the bottom of the impregnation vessel, cooled, and fed to the high pressure inlet line for the high pressure transfer device.
  • a two vessel continuous digester system for digesting cellulosic fibrous material including the following elements: An impregnation vessel having a top and a bottom, an inlet for cellulosic fibrous material slurry to be digested at the top of the impregnation vessel, and an outlet for slurry from the bottom of the impregnation vessel, and an outlet for recirculating liquid from the top of the impregnation vessel.
  • a circulatory system for feeding slurry to the top of the impregnation vessel, and receiving recirculating liquid from the top of the impregnation vessel.
  • a continuous digester having a top and a bottom, an inlet for cellulosic fibrous material slurry to be digested at the top of the digester, an outlet for digested pulp at the bottom of the digester, and an outlet for recirculating liquid from the top of the digester.
  • a first conduit extending between the impregnation vessel slurry outlet and the digester scurry inlet, and a second conduit extending between the recirculating liquid outlet at the top of the digester and the bottom of the impregnation vessel.
  • At least one DOM-reducing serein assemblies between the top and bottom of the digester. Means for withdrawing a.
  • means for augmenting the flow of liquid in the circulatory system comprising means for withdrawing liquid from the second conduit, means for cooling the withdrawn liquid, and means for introducing the cooled withdrawn liquid into the circulatory system.
  • the circulatory system typically includes a high pressure transfer device and a high pressure pump having an inlet and an outlet, the high pressure pump being connected to the high pressure pump outlet.
  • the means for introducing the cooled withdrawn liquid into the circulatory system comprises means for introducing the cooled withdrawn liquid into a conduit connected to the high pressure pump inlet.
  • the system also preferably further comprises means for adding cooking liquor to the withdrawn liquid, e.g. adding the cooking liquor before the means for cooling the withdrawn liquid.
  • the means for cooling the withdrawn liquid preferably comprises a heat exchanger cooler, or an evaporative cooler
  • the digester also preferably includes an extraction screen assembly, and the at least one DOM-reducing screen assemblies comprise a trim screen assembly located adjacent the top of the digester, any a cooking screen assembly disposed between the trim screen assembly and the extraction screen.
  • the digester preferably further includes a wash screen assembly located between the bottom of the digester and the extraction screen assembly, and farther comprising means for adding cooking liquor to the wash screen assembly blanked recirculation pipe disposed in the digester at the extraction screen assembly, so that the extraction screen assembly may be readily modified to comprise a recirculating screen assembly
  • the digester may further include a combined recirculating and extraction screen assembly adjacent the top of the digester; and the at least one DOM-reducing screen assemblies preferably includes a first screen assembly disposed below the combined recirculating and extraction screen assembly, and a second screen assembly disposed below the first screen assembly. Also provided may be a wash screen assembly located between the bottom of the digester and the second screen assembly, and means for adding cooking liquor to the wash screen assembly
  • a method utilizing such apparatus may be practiced.
  • the method comprises the following steps: a) At at least one location between the top and bottom of the digester, withdrawing DOM containing liquid from the interior of the digester, splitting the liquid into first and second flows, and passing the first flow to recovery. (b) Adding low DOM containing liquid to the second flow, including white liquor, and recirculating the second flow back to the interior of the digester; and (c) augmenting the flow liquid in the circulatory system by withdrawing liquid from the second conduit, cooling the withdrawn liquid, and introducing the cooled withdrawn liquid into the circulatory systems.
  • the circulatory system includes a high pressure transfer device and a high pressure pump having an inlet and an outlet, the outlet being connected to the high pressure transfer device, in which case step (c) is practiced by introducing the cooled withdrawn liquid into a conduit connected to the high pressure pump inlet, and is preferably further practiced by adding white liquor to the withdrawn liquid (e. g. buy adding the cooking liquor to the withdrawn liquid before cooling the withdrawn liquid).
  • white liquor e. g. buy adding the cooking liquor to the withdrawn liquid before cooling the withdrawn liquid.
  • the amount of white liquor to the material prior to the digester is about 55% or less of the total amount of white liquor added.
  • the cooling in step (c) may be practiced by heat exchange or evaporative cooling.
  • the method also typically includes the further steps of withdrawing and recirculating liquid in a wash loop at the bottom of the digester and adding white liquor to the wash loop, and extracting liquid from the digester and passing it to recovery distinct from the wash loop and the first portion of the withdrawn liquid passed to recovery from step (a).
  • steps (a) and (b) are practiced at a plurality of different levels within the digester
  • a procedure for controlling the level of liquid in a vapor (steam) phase digester may also be provided particular means and a procedure for controlling the level of liquid in a vapor (steam) phase digester. Going against conventional wisdom, which is that it is not beneficial to extract liquor shortly after impregnation during kraft cooking, according to this aspect of the invention, an extraction from near the top of the vessel may be led into operative association with the level.tank associated with the feed system for the digester assembly, either directly connected to a conduit leading to the level tank in a single vessel vapor phase system, or to the sluice flow of the high pressure transfer device if a two vessel vapor phase system is utilized.
  • a vapor phase digester assembly comprising the following components: A continuous digester having a top and a bottom, including a comminuted cellulosic fibrous material inlet at the top of the digester, and a pulp outlet at the bottom of the digester. At least one DOM-reducing screen assembly for withdrawing liquid having a first concentration of DOM, reducing the DOM concentration so that it is at a second concentration, much less than the first concentration, and then reintroducing the second DOM concentration liquid into the interior of the digester.
  • a feed system for feeding a slurry of comminuted cellulosic fibrous material to the top of the digester including a high pressure transfer device, a chip chute connected to the high pressure transfer device, a high pressure pump connected to the high pressure transfer device, circulatory conduits leading between the high pressure transfer device and the top of the ,digester, and a level tank operatively connected to the chip chute, and a means for removing liquor from the interior of the digester, this means providing for gross control of the level of liquid in the top of the digester to maintain a vapor phase at the very top of the digester.
  • characteristic of the invention means for effecting fine control of the level of liquid in the top of the digester to maintain a vapor phase at the very top of the digester, the means for effecting fine control comprising: a level control screen located below the liquid level adjacent the top of the vessel, but above other screens; a conduit leading from the level control screen and splitting into first and second branches, the first branch recirculating liquid to the interior of the digester, and the second branch operatively connected to the level tank to facilitate fine control of the liquid level in the digester.
  • the assembly typically also includes means for cooling the liquid in the second branch between the digester and the level control tank, and a third branch branching off of the second branch, the third branch leading to recovery.
  • Valve means may also be provided for controlling the relative amount of liquid flowing in the second and third branches.
  • a two vessel system may also be utilized, in which an impregnation vessel disposed between the high pressure transfer device and the digester in the circulatory conduits, and including a sluice conduit.
  • the second branch is connected to the sluice conduit.
  • the invention also relates to a method of treating comminuted cellulosic fibrous material using this system, including a continuous digester having a top and a bottom, including a comminuted cellulosic fibrous material inlet at the top of the digester, and a pulp outlet at the bottom of the digester.
  • the method comprises the following steps: At at least one location in the digester, effecting reduction of the DOM of the liquid in the digester by withdrawing liquid having a first concentration of DOM, reducing the DOM concentration so that it is at a second concentration, much less than the first concentration, and then reintroducing the second DOM concentration liquid into the interior of the digester.
  • Feeding a slurry of comminuted cellulosic fibrous material to the top of the digester including using a high pressure transfer device, a chip chute connected to the high pressure transfer device, a high pressure pump connected to the high pressure transfer device, circulatory conduits leading between the high pressure transfer device and the top of the digester, and a level tank operatively connected to the chip chute.
  • the method may also comprise then further step of cooling the liquid in the second branch between the digester and the level control tank.
  • a third branch branching off of the second branch here may be the further steps of leading the third branch to recovery, and controlling the relative amount of liquid flowing in the second and third branches.
  • an extraction is taken from the outlet of the feed system make-up liquor pump.
  • This allows the removal of DOM-rich liquor from the feed systems (which is particularly advantageous since in means the DOM level at the beginning of the cook is less), while retaining fines or pin chips that may be present.
  • the in-line drainer may be used with a single vessel or two vessel system, and with hydraulic or vapor phase digesters.
  • first and second screens inside the digester, and at least one liquid re-introduction conduit for reintroducing liquid withdrawn through the extraction/dilution screens adjacent the volume of withdrawal, and having a liquid introducing opening therein.
  • the first and second screens are vertically spaced from each other, the closest portions of the first and second screens spaced from each other a first distance.
  • the liquid introducing opening in the re-introduction conduit is' closest to the second screen and spaced from the closest portion of the second screen a second distance.
  • the first distance is 0-305 cm (0-10 feet), preferably about 122-183 cm (4-6 feet), and the second distance is 0-305 cm (0-10 feet), preferably about 91-183 cm (3-6 feet).
  • the second screen is vertically above the first screen and the reintroduction conduit opening is above seconde screen.
  • the second screen is vertically below the first screen and the reintroduction conduit opening is below the second screen.
  • one or both of the screens is connected to a flash tank through the withdrawal conduit, and at least one of the screens is connected to the reintroduction conduit.
  • the digester also topically further comprising at least one screen assembly for withdrawing DOM rich liquid, splitting the liquid into first and second flows, passing the first flow to recovery; and adding low DOM liquid to the second flow and reintroducing the second flow to the digester to reduce the concentration of DOM in the digester
  • FIGURE 1 illustrates an exemplary two vessel hydraulic digester system 10, which includes a circulation to augment the flow to the feed system of the digester assembly. This aspect of the invention is equally applicable to a two vessel vapor phase system, however.
  • the system 10 includes a high pressure transfer device 11 connected to a chip chute 12 which feeds chips (or other comminuted cellulosic fibrous material) to the low pressure input of the device 11, and the output 13 from a high pressure pump 14 is connected to the high pressure inlet of the device 11, the output from the device 11 including a first conduit 15 transporting slurry from the output of the device 11 to the top of an impregnation vessel 16, and the input to the pump 14 comprise a second conduit 17 which recirculates liquid separated from the slurry at the top of the vessel 16
  • the vessel i6 preferably includes a central screen 18 which withdraws liquid from the interior of the vessel 16 and passes it through a cooler 19 before feeding it to the second conduit 17; white liquor may be added in line 20 just before cooler 19.
  • the second vessel of the system 10 comprises the upright continuous digester 21 having a top 22 and bottom 23. Slurry from the bottom of impregnation vessel 16 passes in the first conduit 24 to the top 22, while the second conduit 25 returns liquid separated from the top 22 (through screen 26) to the bottom of vessel 16, typically through BC heaters 26.
  • a trim screen assembly 28 is disposed adjacent the top 22, and includes a withdrawal conduit 29, pump 3'0, heater 31, and re-introduction conduit 32.
  • the withdrawal conduit 29 includes a first branch 33 which is connected to the conduit 32, and a second branch 34 which goes to recovery (e. g. a flash tank), the branch 34 removing DOM-rich liquid from the digester.
  • the liquid flow in branch 33 is augmented by low effective-DOM liquid, in the embodiment illustrated in FIG. 1 a combination of cold blow filtrate and white liquor.
  • a cooking screen assembly 35 is disposed below screen assembly 28, having components comparable to those for assembly 28, and below the assembly 35 is an extraction screen 36 having a withdrawal conduit 37 leading to recovery (a flash tank), and a blanked recirculation pipe 38 is provided above the screen 36.
  • the pipe 38 is provided so as to allow flexibility is the operation of the digester 21, allowing the screens 36 to be connected up as are the screens 28, 35 if desired.
  • the wash circulation 39 is provided at the bottom of the vessel 21, and white liquor may be added thereto in fire 40, in the practice of extended modified continuous cooking.
  • the flow in the circulatory system is augmented by withdrawing liquid from the conduit 25, in line 41, and passing it to the circulatory system, for example to the line 42 connected to the conduit 17. Since the temperature of the liquid in line 41 is high enough that it might cause flashing of some liquid in the device 11, and thus hammering, preferably the liquid passes through cooler 43.
  • the cooler 43 may be an indirect heat exchanger, or an evaporative cooler.
  • white liquor is added to the line 42 prior to the cooler 43, the amount of white liquor in lines 42 and 20 being about 40-55% of the total effective alkali needed for kraft cooking in the digester 21.
  • the flow in line 17 may be augmented by withdrawal through screen 18 of vessel 16, as illustrated in FIGURE 1.
  • FIGURE 2 shows an embodiment similar to that of FIGURE 1 except for the particular circulations in the digester 21.
  • components the same as those in the FIGURE 1 embodiment are indicated by the same reference numeral.
  • the top circulation 44 associated with top screen 45 has a branch conduit 46 through which some DOM-rich liquid is passed to recovery, while the other part is recirculated.
  • the screen assembly 47 is between the assemblies 35, 39, which is like the screen assembly 28 (and components thereof) in the FIGURE 1 embodiment
  • the impregnation vessel, line 41, cooler 43, and other components are the same in this embodiment as in the FIGURE 1 embodiment.
  • FIGURE 3 shows an embodiment of digester 11 in which the line 25 thereof is connected to the impregnation vessel, line 41, coolers 43, and other components as in the FIGURE 1 embodiment, and an additional screen assembly 48.
  • the liquid recirculated via assembly 48 has white liquid and low effective-DOM liquid added thereto before it is recirculated, providing a countercurrent washing zone, providing an additional level of DOM-reduced dilution to the wash zone.
  • a single vessel vapor phase digester system is illustrated generally by reference numeral 50, components in this embodiment comparable to those in the FIGURE 1 embodiment shown by the same reference numerals.
  • the digester 51 is a vapor phase digester, having a liquid level -- illustrated schematically at 52 in FIGURE 4 -- adjacent the top 22 thereof, with vapor (steam) above the level 52.
  • the level 52 of the liquid adjacent the top of digester 51 is primarily controlled by an extraction flow through line 67 from extraction screen 66.
  • the feed system of the digester, systemic in FIGURE 4 includes the level tank 53, connected to an in-line drainer 54 (in turn connected to chip chute 12), a make-up liquor pump 55, and a source of white liquor
  • a third branch 61 is also provided, which ultimately passes to flash tank 62 (recovery), and a valve means 63 may be provided at the junction between branches 59, 61 to control the relative amount of liquid flowing in the branches 59, 61 (i. e. to level tank 53, or to recovery 62).
  • the digester 51 also includes various other circulations, e. g. circulation 64, which is supplied with dilution liquid to reduce the effective DOM concentration in the digester 51, a wash circulation 65, and an extraction screen 66.
  • circulation 64 which is supplied with dilution liquid to reduce the effective DOM concentration in the digester 51
  • wash circulation 65 which is supplied with dilution liquid to reduce the effective DOM concentration in the digester 51
  • extraction screen 66 e.g. circulation 64, which is supplied with dilution liquid to reduce the effective DOM concentration in the digester 51.
  • FIGURE 5 illustrates an embodiment similar to that of FIGURE 4 except that a two vessel vapor phase system is provided, including an impregnation vessel 68, a recirculatory line 69 from the vessel 68 to the high pressure transfer device 11, and a flow line 70 from device 11 to the top of vessel 68, and a sluice flow line 70' is provided between the impregnation vessel 68 and digester 51.
  • the flow from line 59 preferably passes into the sluice flow line 70', although it can also lead to tank 53 or to line 70.
  • FIGURE 5 also shows other apparatus for controlling the level of DOM in the cooking process, including the conventional in-line drainer 71, an inlet line 72 thereto, and outlet line 73 therefrom, and a "drain" line 74 that passes DOM-rich liquid to flash tank 62
  • the inlet line 72 is preferably connected to the output from the make-up liquor pump 55.
  • the line 73 is a liquid line connected to the top of the vessel 68.
  • the in-line drainer 71 is conventional, and is illustrated in more detail in FIGURE 6. It includes an interior screen 75, which is effective to separate out some of the DOM rich liquid that is introduced in line 72, but not fines or pin chips, which stay in the circulation through lines 72, 73.
  • FIGURE 7 schematically illustrates a digester 75 having at least one set of extraction/dilution screens 76, such as first screen 77 and second screen 78 vertically spaced from each other.
  • the screens 77, 78 are between the top and bottom of the digester, topically at a central portion thereof.
  • a first withdrawal line 79 extends from screen 77, and a second withdrawal line 80 extends from screen 78, withdrawing liquid from a withdrawal volume within the digester 75.
  • At least one liquid re-introduction conduit 81 is provided for reintroducing liquid withdrawn from one of the screens 77, 78 (e. g. from line 80) into the digester 75 adjacent the volume of withdrawal.
  • the conduit 81 has a liquid introducing opening 82 therein, typically at the bottom end thereof.
  • the screens 77, 78 are spaced apart a first vertical distance X, which is dependent upon the species being cooked, the diameter of the digester 75, and numerous other variables.
  • the distance X is within the range of 0-305 cm (0-10 feet), preferably about 122-183 cm (4-6 feet).
  • the second distance (vertical spacing) "d" of the opening 82 from the closest portion of the second screen 78 is provided.
  • the distance d is also highly dependent upon the variables of the cook and the digester, and is between 0-305 cm (0-10 feet), typically about 91-183 cm (3-6 feet).
  • FIGURE 7 illustrates an embodiment in which there is co-current flow of'the chips and liquid, the opening 82 being provided vertically below the second screen 78.
  • FIGURE 8 embodiment countercurrent flow between liquid and chips is provided.
  • all components are the same as in the FIGURE 7 embodiment, except that the opening 82 is vertically above second screen 78 (which is above first screen 77 in this embodiment), and typically the exact connections of the withdrawal conduits 79, 80 are different
  • FIGURES 9a-9d schematically show other embodiments of single vessel hydraulic digesters according to the present invention which have various extraction and dilution locations providing great versatility to accommodate different materials being cooked, bleachability and strength requirements, etc.
  • FIGURE 9a The basic difference between the FIGURE 9a construction and that of FIGURE 20 of WO 94/25668 published 10.11.94 is the use of a single cooking circulation 85 in the digester 86 instead of two cooking circulations.
  • the FIGURE 9a embodiment is for furnish that is easier to cook, for example hardwood, and is more economical that a two-circulation digester.
  • An extraction screen 87 is below the cooking circulation 85, a modified continuous cooking circulation 88, with white liquor addition) is below that, and a wash circulation 89 with white liquor addition (for extended modified continuous cooking) in an EMCC ® digester 86 adjacent the bottom.
  • each of the circulations 85, 88, and 89 includes a pump, indirect (steam) heater, and like conventional components. Two extractions are provided for the digester 86.
  • FIGURES 9b-d embodiments components similar to those in the FIGURE 9a embodiment are shown by the same reference numeral.
  • FIGURE 9b embodiment is the same as that of FIGURE 9a except that for the circulation 88 an additional extraction 90, with added dilution 91 to make up for what was extracted, is provided, to reduce DOM concentration further and/or in a more precisely controlled manner than in the FIGURE 9a embodiment.
  • the FIGURE 9c embodiment is the same as the FIGURE 9a embodiment except that the extraction screen 87 is below the modified continuous cooking circulation 88, no dilution liquid is added to the cooking circulation 85, and dilution liquid is added with white liquor in the modified continuous cooking circulation 88.
  • the FIGURE 9d embodiment is identical to the FIGURE 9a embodiment except that the extraction screen 87 and modified continuous cooking circulation 88 are simply switched, and dilution liquid is added to circulation 88.
  • FIGURES 9a-d allow optimization of the DOM concentration profile base upon furnish and desired pulp properties (e. g. strength or bleachability) in a single vessel system while providing improved energy economy. While these embodiments are shown with a single vessel hydraulic digester 86, they may also be utilized with a single vessel vapor phase digester.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)

Claims (13)

  1. Système de lessiveur en continu en phase vapeur comprenant :
    un lessiveur en continu (51) ayant un sommet et un fond, incluant une entrée de matière fibreuse cellulosique broyée au sommet du lessiveur, et une sortie de pâte au fond du lessiveur ;
    un système d'introduction pour introduire une suspension épaisse de matière fibreuse cellulosique broyée au sommet du lessiveur, incluant un dispositif de transfert haute pression (11), une goulotte à copeaux (12) reliée au dispositif de transfert haute pression, une pompe haute pression (14) reliée au dispositif de transfert haute pression, des conduits de circulation entre le dispositif de transfert haute pression (11) et le sommet du lessiveur (51), et un réservoir de niveau (53) relié de manière fonctionnelle à la goulotte à copeaux (12) ; et
    un moyen (67) pour réaliser un contrôle grossier du niveau de liquide au sommet du lessiveur (51) pour maintenir une phase vapeur tout au sommet du lessiveur par retrait de liqueur de l'intérieur dudit lessiveur ;
    caractérisé par
    au moins un ensemble de tamis réduisant les DOM (56 ; 64) pour retirer un liquide ayant une première concentration de DOM, réduire la concentration de DOM de sorte qu'elle soit à une seconde concentration, bien inférieure à la première concentration, puis réintroduire le liquide à seconde concentration de DOM à l'intérieur du lessiveur ; et
    des moyens (56-60) pour réaliser un contrôle fin du niveau de liquide au sommet du lessiveur (51) pour maintenir une phase vapeur au sommet du lessiveur, lesdits moyens pour réaliser un contrôle fin comprenant : un tamis de contrôle de niveau (56) situé en dessous du niveau de liquide (52) en position adjacente au sommet de la cuve, mais au-dessus d'autres tamis ; un conduit (57) menant dudit tamis de contrôle de niveau et se divisant en première (58) et seconde (59) branches, ladite première branche faisant recirculer du liquide à l'intérieur dudit lessiveur, et ladite seconde branche étant reliée de manière fonctionnelle audit réservoir de niveau (53) pour faciliter le contrôle fin du niveau de liquide dans ledit lessiveur.
  2. Système selon la revendication 1, comprenant en outre un moyen (60) pour refroidir le liquide dans la seconde branche entre ledit lessiveur (51) et ledit réservoir de contrôle de niveau (53).
  3. Système selon la revendication 1 ou 2, comprenant en outre une troisième branche (61) partant de ladite seconde branche, ladite troisième branche conduisant à la récupération.
  4. Système selon la revendication 3, comprenant en outre un moyen formant vanne (63) pour contrôler la quantité relative de liquide circulant dans lesdites seconde et troisième branches.
  5. Système selon l'une quelconque des revendications 1-4, comprenant en outre une cuve d'imprégnation (68) disposée entre ledit dispositif de transfert haute pression (11) et ledit lessiveur (51) dans lesdits conduits de circulation, et un conduit d'écluse (70') entre ladite cuve d'imprégnation et ledit lessiveur ; et où ladite seconde branche (59) est reliée audit conduit d'écluse.
  6. Système selon l'une quelconque des revendications 1-5, comprenant en outre un égouttoir en ligne (71) disposé dans ledit système d'introduction pour retirer une liqueur riche en DOM dudit système d'introduction et la faire passer à la récupération, tout en retenant les fines et les copeaux en aiguille dans le système d'introduction.
  7. Système selon la revendication 6, comprenant en outre une pompe de liqueur d'appoint (55) incluant un conduit d'évacuation (72) où ledit égouttoir en ligne est disposé dans le conduit d'évacuation de ladite pompe de liqueur d'appoint.
  8. Système selon la revendication 7, où le ledit système d'introduction inclut une cuve d'imprégnation (68) ayant un sommet et un fond, et reliés auxdits conduits de circulation ; et comprenant en outre une entrée de liquide adjacente au sommet de ladite cuve d'imprégnation ; et où ledit égouttoir en ligne est relié (par 72, 73) entre ladite entrée de liquide au sommet de ladite cuve d'imprégnation et ladite pompe d'appoint (55).
  9. Système selon l'une quelconque des revendications précédentes, où ledit au moins un ensemble de tamis réduisant les DOM comprend des premier (77) et second (78) tamis séparés verticalement l'un de l'autre, ledit moyen pour faire recirculer la liqueur réintroduisant la liqueur au-dessus desdits premier et second tamis ou en dessous desdits premier et second tamis selon que le lessiveur a une situation d'écoulement à contre-courant ou une situation d'écoulement à co-courant, respectivement.
  10. Système selon la revendication 9, où lesdits premier (77) et second (78) tamis sont séparés par une distance d'environ 1,2-1,8 m.
  11. Système selon la revendication 9 ou 10, où une ouverture d'introduction de liquide (82) dans un conduit de réintroduction (81) est séparée de la partie la plus proche du tamis d'une distance d'environ 0,9-1,8 m.
  12. Procédé de traitement de matière fibreuse cellulosique broyée au moyen d'un lessiveur en continu ayant un sommet et un fond, une entrée de matière fibreuse cellulosique broyée au sommet du lessiveur, et une sortie de pâte au fond du lessiveur, le procédé comprenant les étapes suivantes : à au moins un emplacement dans le lessiveur, réaliser une réduction des DOM du liquide dans le lessiveur par retrait d'un liquide ayant une première concentration de DOM, réduire la concentration de DOM de sorte qu'elle soit à une seconde concentration, bien inférieure à la première concentration, puis réintroduire le liquide à la seconde concentration de DOM à l'intérieur du lessiveur ; introduire une suspension épaisse de matière fibreuse cellulosique broyée au sommet du lessiveur, incluant l'utilisation d'un dispositif de transfert haute pression ; réaliser un contrôle de niveau grossier du niveau de liquide au sommet du lessiveur pour maintenir une phase vapeur tout au sommet du lessiveur ; et réaliser un contrôle fin du niveau de liquide au sommet du lessiveur pour maintenir une phase vapeur au sommet du lessiveur, par retrait de liquide en dessous de la phase vapeur au sommet du lessiveur, mais à proximité du sommet de la cuve, diviser le liquide retiré en une première et seconde branches, faire recirculer le liquide dans la première branche à l'intérieur du lessiveur et faire circuler le liquide dans la seconde branche jusqu'à un réservoir de niveau avant le dispositif de transfert haute pression pour faciliter le contrôle fin du niveau de liquide dans le lessiveur.
  13. Procédé selon la revendication 12, comprenant l'étape supplémentaire de refroidissement du liquide dans la seconde branche entre le lessiveur et le réservoir de contrôle de niveau.
EP04028909A 1993-11-08 1994-07-20 Réalisation du profil des matières solides dissoutes Expired - Lifetime EP1538256B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US08/148,269 US5536366A (en) 1993-05-04 1993-11-08 Digester system for implementing low dissolved solids profiling
US148269 1993-11-08
EP94923552A EP0734469B1 (fr) 1993-11-08 1994-07-20 Realisation de la regulation des niveaux de solides dissous

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
EP94923552A Division EP0734469B1 (fr) 1993-11-08 1994-07-20 Realisation de la regulation des niveaux de solides dissous

Publications (3)

Publication Number Publication Date
EP1538256A2 EP1538256A2 (fr) 2005-06-08
EP1538256A3 EP1538256A3 (fr) 2006-01-25
EP1538256B1 true EP1538256B1 (fr) 2008-01-23

Family

ID=22525038

Family Applications (4)

Application Number Title Priority Date Filing Date
EP94923552A Expired - Lifetime EP0734469B1 (fr) 1993-11-08 1994-07-20 Realisation de la regulation des niveaux de solides dissous
EP97118114A Expired - Lifetime EP0822288B1 (fr) 1993-11-08 1994-07-20 Lessiveur en continu pour la réalisation de la régulation des niveaux de solides dissous
EP07119409A Expired - Lifetime EP1878827B8 (fr) 1993-11-08 1994-07-20 Mise en oeuvre de profilage de solides dissous
EP04028909A Expired - Lifetime EP1538256B1 (fr) 1993-11-08 1994-07-20 Réalisation du profil des matières solides dissoutes

Family Applications Before (3)

Application Number Title Priority Date Filing Date
EP94923552A Expired - Lifetime EP0734469B1 (fr) 1993-11-08 1994-07-20 Realisation de la regulation des niveaux de solides dissous
EP97118114A Expired - Lifetime EP0822288B1 (fr) 1993-11-08 1994-07-20 Lessiveur en continu pour la réalisation de la régulation des niveaux de solides dissous
EP07119409A Expired - Lifetime EP1878827B8 (fr) 1993-11-08 1994-07-20 Mise en oeuvre de profilage de solides dissous

Country Status (8)

Country Link
US (3) US5536366A (fr)
EP (4) EP0734469B1 (fr)
JP (1) JP3126386B2 (fr)
AU (1) AU7338594A (fr)
CA (2) CA2222661C (fr)
FI (1) FI121789B (fr)
WO (1) WO1995013419A1 (fr)
ZA (1) ZA947434B (fr)

Families Citing this family (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5489363A (en) * 1993-05-04 1996-02-06 Kamyr, Inc. Pulping with low dissolved solids for improved pulp strength
SE502134C2 (sv) * 1994-02-10 1995-08-28 Kvaerner Pulping Tech Optimering av vätske/ved-förhållande i förimpregneringskärl och kontinuerlig kokare vid framställning av kemisk massa
US6174411B1 (en) * 1997-02-10 2001-01-16 Andritz-Ahlstrom Inc. Continuous digester with inverted top separator
US5882477A (en) * 1997-02-10 1999-03-16 Ahlstrom Machinery, Inc. Continuous digester with a low temperature gas-phase
US6139689A (en) * 1997-06-11 2000-10-31 Beloit Technologies, Inc. Apparatus for digesting pulp in a displacement batch digester that uses displacement liquor having a sufficient hydrostatic head
US5985096A (en) * 1997-09-23 1999-11-16 Ahlstrom Machinery Inc. Vertical pulping digester having substantially constant diameter
US6241851B1 (en) 1998-03-03 2001-06-05 Andritz-Ahlstrom Inc. Treatment of cellulose material with additives while producing cellulose pulp
US6277240B1 (en) 1998-10-02 2001-08-21 Andritz-Ahlstrom Inc. Method for continuously pulping cellulosic fibrous material
US20010032711A1 (en) * 1998-10-26 2001-10-25 C. Bertil Stromberg Pulp cooking with particular alkali profiles
US6368453B1 (en) * 1999-03-18 2002-04-09 Andritz Inc. Chip feeding to a comminuted cellulosic fibrous material treatment vessel
CA2318027C (fr) 1999-09-13 2008-07-08 Andritz-Ahlstrom Inc. Traitement de la pate a papier avec un additif ameliorant le rendement ou la resistance
US6451172B1 (en) 2000-05-18 2002-09-17 Andritz Inc. In-line drainer enhancements
US6436233B1 (en) 2000-05-18 2002-08-20 Andritz Inc. Feeding cellulose material to a treatment vessel
FI119107B (fi) * 2001-11-06 2008-07-31 Metso Paper Inc Järjestely sihdin asentamiseksi
US20030131956A1 (en) * 2002-01-16 2003-07-17 Stromberg C. Bertil Continuous pulping processes and systems
US7125472B2 (en) * 2002-07-11 2006-10-24 Jack T. Baker Slotted screen for digester
US7115189B2 (en) * 2002-07-11 2006-10-03 Jack T. Baker Slotted screen for digester
SE527058C2 (sv) * 2004-02-09 2005-12-13 Kvaerner Pulping Tech Kontinuerlig kokprocess med förbättrad värmeekonomi
US7452444B2 (en) * 2004-05-26 2008-11-18 International Paper Company Digester wash extraction by individual screen flow control
US7241363B2 (en) * 2004-06-26 2007-07-10 International Paper Company Methods to decrease scaling in digester systems
JP4995085B2 (ja) * 2004-08-05 2012-08-08 インターフェイス，インコーポレイテッド 廃材からのナイロン抽出方法
SE531067C2 (sv) * 2005-09-15 2008-12-09 Metso Fiber Karlstad Ab Kontinuerlig kokare med vätskecirkulation
US20070240837A1 (en) * 2006-04-13 2007-10-18 Andritz Inc. Hardwood alkaline pulping processes and systems
AU2007253774C1 (en) * 2006-05-19 2012-03-22 The Research Foundation Of State University Of New York Methods for carbonate pretreatment and pulping of cellulosic material
US7828930B2 (en) * 2007-11-20 2010-11-09 International Paper Company Use of polysulfide in modified cooking
US8303767B2 (en) * 2008-03-18 2012-11-06 The Research Foundation Of State University Of New York Methods of pretreating comminuted cellulosic material with carbonate-containing solutions
SE532855C2 (sv) * 2008-10-13 2010-04-20 Metso Fiber Karlstad Ab Förfarande för att förhindra igensättning i en silkonstruktion för en kontinuerlig kokare
JP5222183B2 (ja) * 2009-03-03 2013-06-26 正夫 金井 連続式乾燥装置
EP2436837B1 (fr) 2009-05-26 2018-09-19 Nippon Paper Industries Co., Ltd Procédé pour lessiver un matériau lignocellulosique
US9228575B2 (en) * 2010-11-16 2016-01-05 Zoeller Pump Company, Llc Sealed and self-contained tankless water heater flushing system
US8894819B2 (en) * 2012-04-25 2014-11-25 Andritz Inc. In-line drainer with shaped screen slots
US8986504B1 (en) 2013-10-25 2015-03-24 International Paper Company Digester apparatus
TR201409682A2 (tr) * 2014-08-19 2016-03-21 Univ Istanbul Teknik Bir yığın delignifikasyonu.
SE538452C2 (en) * 2014-11-07 2016-07-05 Valmet Oy Method for operating a two vessel digester system

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3303088A (en) * 1963-04-19 1967-02-07 Lummus Co Continuous liquid-phase rapid pulping
US3215588A (en) * 1963-08-15 1965-11-02 Lummus Co Continuous impregnation, cooking, and washing of fibrous material
FI44514B (fr) * 1963-12-13 1971-08-02 Kamyr Ab
SE331627B (fr) * 1965-01-29 1971-01-04 Kamyr Ab
SE359331B (fr) * 1970-03-17 1973-08-27 Kamyr Ab
US4071399A (en) * 1976-09-01 1978-01-31 Kamyr, Inc. Apparatus and method for the displacement impregnation of cellulosic chips material
FI63610C (fi) * 1981-12-31 1983-07-11 Ekono Oy Foerfarande foer kontinuerlig uppslutning av finfoerdelat material
SE452482B (sv) * 1982-04-28 1987-11-30 Sunds Defibrator Forfarande for satsvis framstellning av sulfatmassa med hog delignifieringsgrad
SE453840B (sv) * 1984-12-21 1988-03-07 Mo Och Domsjoe Ab Forfarande vid framstellning av cellulosamassa
US5300195A (en) * 1988-05-31 1994-04-05 Kamyr Ab Continuous vertical digester apparatus
US5053108A (en) * 1989-06-28 1991-10-01 Kamyr Ab High sulfidity cook for paper pulp using black liquor sulfonization of steamed chips
CA2037717C (fr) * 1990-09-17 1996-03-05 Bertil Stromberg Cuisson prolongee de pate kraft avec ajout d'eau blanche dans le circuit de recirculation
ATE125010T1 (de) * 1990-09-20 1995-07-15 Kvaerner Pulping Tech Tränkung mit schwarzlauge vor der zufuhr der weisslauge.
US5401361A (en) * 1992-08-19 1995-03-28 Kamyr, Inc. Completely coutercurrent cook continuous digester
US5302247A (en) * 1992-11-02 1994-04-12 Kamyr, Inc. Top circulation line cooling for a modified cook digester
US5489363A (en) * 1993-05-04 1996-02-06 Kamyr, Inc. Pulping with low dissolved solids for improved pulp strength
US5320247A (en) * 1993-09-01 1994-06-14 Sharp Bruce R Storage tanks with internal support ribs

Also Published As

Publication number Publication date
CA2175666C (fr) 2004-03-02
EP0822288A3 (fr) 1998-10-28
EP1878827B1 (fr) 2011-06-15
FI961921A0 (fi) 1996-05-06
CA2222661C (fr) 2005-03-22
EP1878827B8 (fr) 2011-10-05
FI961921A (fi) 1996-06-20
EP0734469B1 (fr) 2005-02-23
CA2175666A1 (fr) 1995-05-18
CA2222661A1 (fr) 1995-05-18
JPH09504842A (ja) 1997-05-13
JP3126386B2 (ja) 2001-01-22
EP0822288B1 (fr) 2007-11-07
EP0734469A1 (fr) 1996-10-02
US5536366A (en) 1996-07-16
EP0822288A2 (fr) 1998-02-04
US5849151A (en) 1998-12-15
US5662775A (en) 1997-09-02
ZA947434B (en) 1995-05-15
AU7338594A (en) 1995-05-29
EP1538256A2 (fr) 2005-06-08
EP1538256A3 (fr) 2006-01-25
WO1995013419A1 (fr) 1995-05-18
EP1878827A3 (fr) 2008-06-18
FI121789B (fi) 2011-04-15
EP1878827A2 (fr) 2008-01-16

Similar Documents

Publication Publication Date Title
EP1538256B1 (fr) Réalisation du profil des matières solides dissoutes
US6159337A (en) Dissolved organic materials control in cellulose pulp production
US5213662A (en) Treatment of chips with high temperature black liquor to reduce black liquor viscosity
CA2050818C (fr) Impregnation de boue noire avant l'introduction de l'eau blanche
US6123807A (en) Method for the continuous cooking of pulp
US5401361A (en) Completely coutercurrent cook continuous digester
US5302247A (en) Top circulation line cooling for a modified cook digester
US6203662B1 (en) Method for the continuous cooking of pulp in a digester system having a top separator
US20010000588A1 (en) Method and device for the continuous cooking of chemical pulp
US6325889B2 (en) Hydraulic vessel system having a downwardly feeding separator
US6159336A (en) Method and device for the continuous cooking of pulp
WO1998035090A1 (fr) Procede continu de production de pate avec impregnation de liqueur residuaire

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AC Divisional application: reference to earlier application

Ref document number: 0734469

Country of ref document: EP

Kind code of ref document: P

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): SE

17P Request for examination filed

Effective date: 20060428

AKX Designation fees paid

Designated state(s): SE

17Q First examination report despatched

Effective date: 20070507

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AC Divisional application: reference to earlier application

Ref document number: 0734469

Country of ref document: EP

Kind code of ref document: P

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): SE

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20081024

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20130711

Year of fee payment: 20

REG Reference to a national code

Ref country code: SE

Ref legal event code: EUG